#0  ast_format_get_name (format=0x0) at format.c:341
 #1  0x00000000004b6113 in ast_write (chan=0x7ffff0b09d18, fr=fr@entry=0xae8010) at channel.c:5110
#2  0x0000000000484289 in bridge_channel_handle_write (bridge_channel=0x7ffff1038868)
    at bridge_channel.c:2247
#3  bridge_channel_wait (bridge_channel=0x7ffff1038868) at bridge_channel.c:2494
#4  bridge_channel_internal_join (bridge_channel=bridge_channel@entry=0x7ffff1038868)
    at bridge_channel.c:2628
#5  0x000000000046e0c2 in bridge_channel_depart_thread (data=data@entry=0x7ffff1038868)
    at bridge.c:1590
#6  0x00000000005de0da in dummy_start (data=<optimized out>) at utils.c:1237
#7  0x00007ffff6516b50 in start_thread () from /lib/x86_64-linux-gnu/libpthread.so.0
#8  0x00007ffff58987bd in clone () from /lib/x86_64-linux-gnu/libc.so.6
#9  0x0000000000000000 in ?? ()